1. Field of the Invention
This invention generally relates to a display for sharing display data channel (DDC), and more particularly to a display for sharing display data channel by using in system programming (ISP) to update the firmware of the microcontroller.
2. Description of Related Art
As the application of the embedded flash memory has become mature, more and more microcontrollers are embedded with flash memory and provide ISP function. That is, the content of the embedded flash memory can be updated via the interface without removing the flash memory from the circuit board. The prior art uses RS232 or I2C protocol as the interface for ISP. In addition, RS232 is an important interface for the production line in debugging and adjusting the products.
However, the display generally does not provide RS232 or I2C interfaces. Hence, when performing ISP or adjustment, a particular tool is required to connect the circuit board. After the ISP or adjustment is performed, this particular tool will be removed. The drawback of the prior art is that after the display is assembled, it is impossible to reconnect the particular tool to the circuit board for performing ISP or adjustment.
To improve the prior art, a 9-pin RS232 connector has been added on the display for performing ISP or adjustment on the production line. However, the additional device increases the cost and occupies the space of the display.